There's nothing we like better in this place than spending other people's money...

So, problems with your current kit:
- Widest you've got is 24mm on a crop body. No interest in landscapes, say a 10-22, 10-20, 11-16, 8-16?
- Long end, the 70-300 non-L is great up to 200mm, it just gets soft at the far reaches. 70-300L is probably out of the budget, so it's 70-200 f/4 non-IS, or sell the 70-300 and save a bit more for the f/4IS or f/2.8 non-IS. The 70-200 f/4 non-IS might not be enough of an upgrade from the 70-300nonL, you lose IS for only a bit better IQ in the overlapping ranges.
- No fast primes, although the f/2.8 zoom does help offset that. You can get a new 50/1.4 and 85/1.8 for that cash, maybe squeeze in a 35/2 or samyang 35/1.4 if you buy all of them second-hand and get a good deal (the 50/1.8 will save some cash if you'd rather get the prime-triplicate, I paid about $300 each on ebay for my second-hand samyang 35/1.4 and EF 85/1.8, leaves $100 for the niftyfifty).
- 135/2 would be very nice, but that's probably all you'd get for the money. Definitely worth the money if it's a length you need.
- Old-body, of the 5D, 50D, 60D, 7D, i'd say saving more for the 7D is the best upgrade, but within the budget the 5D-original is a nice body, you'll get a wider-view from your 24mm and better low-light handling, so goes some way to fixing the 'wide end' and 'fast prime' sections. Either sell the 30D to fund a prime or two as well, or keep it as a backup. I'd go 50D over 60D, and a 1D2 probably isn't worth the 'upgrade' IMHO.
- No mention of tripods/heads/etc, but you may have them and didn't write them down.

So I'd be voting the:
- 50/1.4 + 85/1.8 (plus a 35 if you can get them cheap enough) as first,
- 5D second (with 30D backup),
- and 5D/50D + 85/1.8 (50/1.4 too if you get a good deal) with selling the 30D as third choice.