Electrical connections

What I have used for both soldering and heat shrink is the Bernz-O-Matic butane iron. You can remove the tip and turn it into a micro torch, which is adjustable. they don't work too bad for that. I've found them at either Lowes or HD for under 30 bucks.

So far as a heat gun, there are "budget" choices I have a yellow one made (branded) "Wagner" or some such They have one model showed up on Amazon for 25 bucks