I'm thinking about doing the same thing to my Ranger. I have about $10k to throw at my truck from selling my house. I thought about buying a 2019 FX4 with the Ford Performance upgrade or doing a 5.0 Coyote engine swap but neither worked out. Really didn't want another car payment and the 5.0 swap was looking like $35k-$40k! So I'm now looking at putting a supercharger on my 2007 which I just put an engine with 84k and timing chains done. I came to this forum to ask some questions and saw the thread. Don't mean to hijack it but I think asking the questions here will help others with the same ones. I'm wondering how much boost the SOHC can safely handle, how much boost would be enough to make it worth it and can the transmission handle it? EGR delete is not a problem because, even though MA is a CA compliant state, the truck is over 15 years old and they don't do emissions any longer. The other thing is, my oil fill has like an extention on it and I wonder if the intake tube will run into it.
On the oil fill, I just removed the extension piece and put the oil fill cap under the intake hose. So I need to loosen one screw clamp on the intake hose and remove the hose from the throttle body to fill oil. Big deal, it happens somewhere between once a quarter and once a year. I would not do an egr delete, there are good reasons to keep it. If you read the writeup I did here on TRS about the kit, you will see that I bought a different egr valve that has a different orientation for the inlet. It fits fine and works fine.
How much boost the sohc engine can handle is a bit tricky to answer. The head gaskets are not great on these engines to begin with, and guys who have done a lot of boost say that if you run any boost eventually the head gaskets will let go. I have up to 6-7 psi available but very rarely go over 4 psi boost, and have close to 20k miles on it now with no issues.
What you can get away with before you have to tune really has to do with how much you like to mash your foot to the floor, and how fast you rev the engine. If you almost never rev it past 4k rpm, and if you rarely run over 4 psi boost, the stock tune will be fine. The tune I am running now is not that much different from the stock tune, and I fit the criteria of the last sentence. If you are going to run it harder, then you definitely need a good tune and a larger fuel pump.
If your transmission is in good condition then it will handle the increased power just fine. Sure, it might have a little shorter life, but you are not going to blow it up unless it already has some issue.
As others have mentioned, even 4 psi is a nice improvement. However, if I was in a situation where I didn't have to worry about emissions testing, I would build a nice 5.0 Windsor to about 400hp and 400 ft-lbs and drop that in because that will be much more fun and even more reliable. You could easily build the engine and trans from an Explorer to be bulletproof and install it in the Ranger for the budget you have mentioned.