2 week itinerary help please

Forget beach life in October. The direct Split - Dubrovnik catamaran runs only 3times weekly in October.
Daily boats/catamarans from Split up to Korcula Island (Vela Luka), daily bus from Korcula to Dubrovnik.
A full day is quite a lot for Plitivice. Same remark for Solin.
Nice medieval towns more or less along your itinerary:
Sibenik, Trogir, Split, Hvar, Korcula, Mostar, Dubrovnik, Kotor.

I would not spend that much time in Dubrovnik, though I do think you may want to pick one place that you will relax for a few days. It just would not be Dbv for me.
Even though the season is winding down, the towns of Hvar or Korcula would be nice in between, or Mostar for an overnight in between if that interests you more.
What's after the 26th? {fly out of ?}

catamarans:
http://www.krilo.hr/en/sailing_schedule.html
ferries and cats:
http://www.jadrolinija.hr/
split bus schedules:
http://www.ak-split.hr/EN/

You could do 13-19 by bus, but it would be more time consuming. I think I'd go with a car. I know that Zagreb-Plitvice-Zadar is pretty straightforward with the bus, but I am not as familiar with Krka. Though with a car you need not necessarily transit through Zadar unless you just wanted to.

Thanks so much for the suggestions and information meckerdv and veta. Great to you have your insights, especially into the transport side of things. Will take a look at those websites and factor in all you've said.

Veta- after the 26th we spend a few days in Mostar then head up to Sarajevo for a bit before flying to Istanbul for a trip in Turkey.

Great, then I'd pick Hvar or Korcula for a stopover between Split and Dubrovnik, unless you had a reason for three full days in Dubrovnik.

Thanks Veta. Will look into it :)

I’d use a hire car if you can afford one. Gives you more flexibility and less hassle organising buses and more time to see and do stuff.

Plitvice is fantastic but didn’t go to Krka.

You can look around old Zadar city comfortably in half a day.

I’d suggest going from Split to Dubrovnik by ferry through the islands. We did the following and worked for us –

Split 3 days (came from in by hire car)

Day ferry trip to Hvar from Split.

Ferry to Split to Korcula (left Split late afternoon and arrived early evening with guest house owner meeting us at the harbour).

Korcula 2 days including a day trip to Mljet island (from Korcula)

Mini bus from Korcula to Dubrovnik (which includes a short ferry trip from Korcula to the mainland) Had a reasonable departure time (930am from memory) compared to the bus which was very early. Used the following for the mini bus trip from Korcula to Dubrovnik
http://korkyra.info/about-us/

Split accommodation - Apartments Posejdon & Neptun, was fantastic in the walls of the old city
http://www.booking.com/hotel/hr/osejdon-eptun.en-gb.html?sid=05589ccabe0e77cef1872ac0780c1b42;dcid=4;dist=0;srfid=3d032ea783826e0b0f8a52197950cad5395a4603X1;type=total;ucfs=1&

Korcula accommodation - Guest House Leon, small room but very good and great location (above the travel office mention above)
http://www.booking.com/hotel/hr/guest-house-leon.en-gb.html?sid=05589ccabe0e77cef1872ac0780c1b42;dcid=4;dist=0;srfid=7b3713d62a97a2a64d3e414fb6ddf9ebd301aa8cX1;type=total;ucfs=1&

For Dubrovnik I’d suggest one day as a bare minimum, preferably two.

I’d recommend a walking tour to get you oriented –
www.dubrovnik-walking-tours.com

We did the Discover Dubrovnik walking tour and found it great. Tour guide was a local and very knowledgeable. Went for more than an hour and it was a free walking tour last year (the Croatian govt. is cracking down on free walking tours).

A couple of other highlights – walk around the city walls (do it early or late if there is a cruise ship(s) in town to avoid the crowds), the chair lift and museum at the top showing the history of the siege.

We did the above late September last year. I wouldn't be swimming (but I come from Australia) and you need to check the ferry times as will be after the tourist season. (the tourist office at Split were very helpful with this).

Thanks habby, that's really helpful. Have decided to go with the car. Will check out your accommodation suggestions- fantastic!

Haha I am Australian too. I realise we probably won't be swimming but we still enjoy islands and the sea anyway.

We are still choosing between Hvar and Korcula. Having been to both what would be your choice if you had to pick one for October? (I know its subjective and interested in hearing your perspective!)

I liked Korcula (town) a lot more. The old walled town is still structurally intact and quite fascinating to walk around. Didn’t seem as touristy as Hvar.

For Mostar we stayed at http://www.shangrila.com.ba/en/index.php and would recommend.

We did all our accommodation via booking.com and found to fantastic places. We were booking one or two nights in advance and had plenty of choice.

Thanks habby. Good to hear your opinion on that. Yeah it seems like there is a great choice of accommodation. Cheers!