Best way to play Gamecube? (TV wise)

Ive recently gotten into trying to get the best picture out of my old consoles. 

Ive recently picked up a 36fv310 CRT and an older 720p plasma tv off craigslist / thrift shop, just to see how my old consoles look on them.

I actually do own the mythical Component Cables for my cube, and I also own the Eon GCHD as well.

I also have an Mcable gaming edition.

Problem is, I would like to use 480p on my 4:3 games. My CRT cannot do 480p. my plasma CAN do 480p, but it doesnt look 'the best'. 

The mcable + GCHD looks absolutely awesome, but with older plasmas / LCD tvs, you cannot change the aspect ratio on anything 720p or larger, (mcable upscales to 1080p), so I cannot get that awesome 4:3 480p.

I did play eternal darkness with the mcable in 480p widescreen, and it was jaw droppingly amazing.

I know the best solution here is the PVM-20L5, but Id rather not spend that much money. 

I guess the ultimate question: does an HD CRT (like the 1080i trinitrons) look the best for gamecube games? Is it worth going after one? There are quite a bit in my area for free all the time. (but of course these things weigh like 200 pounds and take up a lot of space...