Upgrading an Epiphone questions

Hey guys!

So I have an epiphone es-339 that I got just a few months ago and I love it. It looks, feels, and sounds great. I have my eye on an MIA tele because I want something that is extremely high value but I also want to upgrade my epiphone. I'm looking to first replace the tuners then maybe put on a Bigsby and last I want to change the pickups (p90's). I want to order the tuners nowish and I can't seem to find out what tuners would work for it so I figured I would ask you guys. Also do you any of you know how I can find a bigsby that will fit the smaller es version and good p90s that won't completely break the bank? And is there anything else I should upgrade?

Thank you!

-Gabe