Need help with some deciding factors 1994 c1500 5.3 swap 4l60e

So, I have a 1994 c1500 with a 5.7 350 tbi, and a 4l60e.

I've already taken out my 350, and I was planning on building it, and swapping it to carb, but I've just now been thinking about an LS motor. I've searched around and haven't found a definite answer to my questions.

How do I deal with the transmission control?
How much should I expect to pay for a basic 5.3l swap? I'm budgeting around 2-3k. Is that enough?
How difficult is the swap?
Should I buy a harness from Current Performance?
How hard is it to make my current 350 harness work with the 5.3?

Any answers to these questions would be of great help! If you need more information, please just ask. Thanks.

I did the swap in my 95 c1500. I used the stock 5spd manual trans so can't help you with your tranny question. I can tell you that you can pretty much cut your entire factory harness out cause it's not usable with the LS pcm. I modified the 5.3 harness to make it stand alone and wired everything into the factory fuse block. You will need to replace your fuel pump in the tank to a high pressure one, and you should replace all your fuel lines to.
Your 350 motor mounts on the frame will work and you will need to buy engine mounts. I used the dirty dingo adjustable mounts. Schoenfeld long tube swap headers. Truck runs awesome, huge improvement from the 4.3 I removed.

How much did the swap cost you? Was the overall engine swap that difficult? And is modifying my wiring harness going to be difficult?

Pretty simple swap I thought. Cost me about 3 grand in the end, but I had to pay a lot of money for parts out of the state's with expensive shipping to.
Lt1swap.com was a life saver for the wiring

your 4l60e can be controlled by the pcm, we can build you a custom stand alone harness for your conversion. This conversion is not too difficult, but it can be time consuming.
For any other questions you can email Ray@nelsonperformance.com