Ok, so as the title suggest, im going to do a little overhaul of my amp/setup.

Im runnin SD blackouts into a Marshall JCM 2000 TSL, now, its usd, and i know the tubes havent been changed out since its been originally purchased, i wanna say in 2002.

I love the sound it gets me and it really opens up once its cranked, im wondering if retubing power tubes and preamp tubes would make a big difference in my tone?

I know certain tubes are better for certain sounds, and that if placed in certain slots it will effect different, but i dont know which ones i want and in which valves i want them in.

I really like american voiced amps, and honestly am not sure were marshall jcm's lie in that category, and i believe it came with 6l6's.. I like playing heavier stuff, but also like my clean cleans and mid heavy crunch, so this comes down to, what all things do i need to ask myself to look for in tubes? and what tubes would you guys reccomend i put in?

I also know some tubes give more gain, which is what im looking for, maybe for that crunch to be a little crunchier, (the lead is really smooth already)..Would tubes do this for me? and will it increase the clarity in the entire amp?

Also, im thinkin about gettin new speakers, (have a celestion cl80, and a celestion k100), im thinking about some v30's or greenbacks, (in a 4x12 closed back), but a question ive been found asking is.. What about PA speakers? I talked to a quite intelligent person about this, and he swears up and down on using PA speakers for amps.

Instead of enhancing certain frequencies and handling them better like guitar speakers, PA speakers cover an extremely wide range of frequencies, and have uncomparable headroom, which makes me think it will handle bass frequencies better, but im not sure? any opinions on this?

LAST question, thinking about getting a tubescreamer to help boost the crunch channel, and give me a niice blues/light rock tone, is it worth it?

TLDR: what new tubes should i get for my TSL? what speakers, and is tubescreamer worth it. will it make it sound noticeably more clear?