D700 lens choices

OK, I know this sort of question is asked all the time, but any advice will be much appreciated.

I recently upgraded from a D200 to a D700. I've got the 50mm 1.8, and also have a 20-35 2.8 and 80-200 2.8 ED (quite an old one, from around 1992).

I do a bit of landscape photography, portraiture, some shots around cities, etc. I am also doing some weddings this year.

I very rarely use the 80-200 because it's just so heavy. I can't be bothered to take it out and carry it round with me. I don't drive, so I'm generally on public transport/walking and it is just too cumbersome. When I do use it, it's usually at 80mm for portraits, I don't think I've really ever used it at 200mm.

I do like the 20-35, but it's also a bit heavy and a pain to take around with me. I only ever use it at 20mm.

I'm considering selling the 20-35 and 80-200 and investing in a couple of primes instead. I feel I'd use some smaller, lighter, less cumbersome lenses more. Also, if they were faster, all the better - especially for the weddings I'm doing.

Both my 20-35 and 80-200 are quite old and not in perfect condition, so I'm thinking I'll be able to get say £600 max for them (I'm in the UK).

My plan is then to invest in the Nikkor 20mm 2.8 and 85mm 1.8. I think I could just about afford these for £600.

I just wondered if anyone had any advice - are there any lenses you'd recommend over the above for my purposes?