Well I posted in the longtail section about Thai long tails and using their shorter shaft. But after speaking with the dealers they do not recommend it at all. So I do not want their rediculously long 85-100 inch long tails sticking off the back of my boat. So I have decided to budget for a better kit.
My boat is a 1636 flat bottom and it will be a multi use boat, hunting and fishing. Most of my fishing will be in open water or in some rocky rivers where I know I will have to be careful on and yes a jet would be better for that situation but I'm not buying one for the few times a year it will see rocks. Hunting will be the norm, timber and shallow areas with mud and veggies.

So first I am looking at the backwater swomp lite frame and putting a predator 420 on it to keep cost down. I hear nothing but good things about this kit and It seems to be very capable. More than I likely need it to do.
Second, a local boat builder has a surface drive frame that he sales for $1200 out the door to mate up to a predator 420. Made with parts that can be bought easily should any issues occur. If I can scrape up the money a copperhead 12 may also be an option but that may or may not happen. I like the way a surface drive seems to handle a little more like a traditional outboard as well as seems to do a little better speed wise. Also it will be less in the way while fishing I would think.

What would you all recommend for my boat and use?

Go as big as you can afford it have a 16x39 skiff had a 40hp ob on it which is 212lbs and wasn't no problem I'm about to put a 50hp on it and thinking about getting a gatortail to swap back n forth to crawfish you want the biggest motor you can afford that way if you ever decide to get a bigger boat u won't be under powered

I ain't ever heard anybody say "Damn!!! I should have gotten a motor with less horse power!!!"

That's what most replies will sound like go as big as you can afford or you will regret it later on

Well I have pretty much settled on the backwater swomp lite series. If bigger is better then I guess we are talking the swomp lite 23. How do you think a 1636 will realistically carry this? It would be awesome to possibly upgrade boats eventually and keep the same motor. But is the 1636 going to support a motor of that size well?

I have a 40hp which is 212lb on a 16x39 you would definately be ok with the 23hp i wouldnt go any less. If it were me id put a 27hp or 35hp on it if you plan on getting a bigger boat one day.

Thanks for the help so far y'all. So the price is the same for the caged swomp 23 and the swomp lite 23. Which of these two would you recommend? With the swomp 23 you can get a 59 inch shaft or a 71. 71 is a little longer than I'd like. You get a 65 inch shaft with the swomp lite which is the longest shaft I'd want I suppose. How would at 59" perform different than a 65"? Which length would be ideal for my boat as well as possibly a 1644 in the future?

With either of those shorter shafts, it's best to run a short transom boat. As far as whether to go with the SWOMP LITE or the full cage frame, I'd call the Backwater shop and let them run you through the differences and you can tell them what the boat will be used for and they'll definitely get you steered in the right direction. Where are you located?

I live in South Carolina about 20 minutes south of Charlotte, North Carolina

I'd go with either with the 65" or the 71" shaft. Later on if you change hulls the longer length has a flatter drive angle which is more efficient.