What are the optimal percentages for analog system

Again. Think about the cartridge you want, then find the arm/table that can handle it BEST. Go to:
http://www.theanalogdept.com/cartridge___arm_matching.htm
for a nice explanation about cartridge/arm matching with examples. Maybe your table/arm will work well after all and you can upgrade that piece last.
What you have isn't bad, but why make a lateral upgrade? Maybe a better table/arm does less damage to your vinyl collection? Maybe it's quieter? Ideally, it should work well with your dream cartridge.
Regarding the phono stage, I think that should be determined by the cartridge you choose. For example, I read that the Grado cartridges sounded better with SS preamps than with tubed preamps. The same article/opinion also felt that MC cartridges sounded better with tubed preamps than SS units. And if you go with MC, you'll need to match the cartridge's output with an appropriate amplifier gain and step up transformer. If you stay with Grado cartridges, they make 2 versions, high and low output. I can tell you personally that with the low output models, your choice in preamps is not that vast. They need a preamp with at least 56db gain, and there aren't too many of those around. I have both versions of the Sonata1 and a Grado PH1, and I prefer the low output Sonata1.
With a MC cartridge, I think you have more choices out there between step up transformers and phono stages. But you should really make sure the MC cartridge mates well with your tonearm. Therefore...get an idea of your dream cartridge, choose your table/arm accordingly. Hopefully, the cartridge you have will work with your new table. Maybe your dream cartridge will work with your old table. It would be a shame to get the new preamp first, then have to toss it because it didn't match well with your cartridge. Preamp should be last. Cartridge vs table/arm depends on whether your dream cartridge will work with your present table.

the grado and belari are not good for each other. both kind of on the low definition, warm and fuzzy side; instead of balancing each others' weaknesses, they add to them. I had a Bellari and hated it, so that would be the first to go, for me.

I haven't had a grado myself but I have read in forums several times that they tend not to match well with Rega's due to motor interference, resulting in hum. That said the pickup's life's finite and you are going to replace it eventually anyway. Otherwise I tend to mostly agree with Elizabeth. The table is capapble of acommodating better gear at both ends. So I would say upgrade the phono stage first and get something able to work with both MM and MC carts unless you want to buy an SUT later as well (that in itself is not at all a bad thing, but it adds another element). For $400-500 used you can pick up a Lehman SE and they sound terrific, belt suspenders and a bag o chips.
Proportions are arcane to me, but I would guess 25, 25,25, 25 to be fair. Generally, and I may get spanked for this by some, I would stay away from used pickups only. Tables are also very tricky to ship.
Myself I went with a good pre with built in MM/MC phono and couldn't be happier.

Since this precise question has been in the forefront of the minds of lazy audio thinkers everywhere, the exact subjective AND objective optimal percentages were calculated by a cadre of respected physicists and mathematicians working for a special United Nations panel convened for this purpose.
The figures are:
Turntable: 27.22%
Pickup: 22.56%
Tonearm: 29.9211%
Speakers: 44.565%
Amplification: 33.432%

Are you for real..???

$10000.00 be a sport.