I'd say:
1. EK9 chassis cause its the stiffest
2. EG chassis cause it's lighter than 6th gen chassis
3. Other 6th gen chassis, not stiffer than EG afaik but heavier
Maybe consider a DC2? Comparable to the EK9 in terms of grip/handling/chassis stifness but with B18c and can be had for (relatively) little money, much cheaper than a 9. Which means you have more money for mods and an engine with more power.
I'd always go with the newer chassis personally. You can lose weight, but you can't always make all the little improvements Honda did between models. Plus, the EG interior is minging...
As above though, it depends what you're looking to spend. If you're thinking of going B18C/K20 conversion, then I'd go for EG. EG's will take more £'s to get up to par/better. EK9/DC2 are 'more out the box' type car's, most goodies/power is there from stock.
If I knew back then what I knew now, back when I was looking for one, I'd probably would of gone, EK9/DC2 ... probably ... However, I do not regret transforming my EG into, what I call, a BEAST ;p - she's worth it, car handles great, great power/weight ratio etc...All depends on how much money you want to throw at it.
In all honestly you wont go wrong with either so I'd concentrate on finding a good, straight rust free shell rather than worrying about which generation to go for.
All depends on the build; if I were to have a stock EK and stock EG. I'd build the EG for weekend/tracks (more into performance than looks) and EK as a daily-driver / show car (more into looks than performance).
If I were to have 2 EK's instead, i'd have a weekend and a daily
2 EGs? I'd rather sale both of them.
I think atm for the cost of making a nice track car you are best with a DC2, Comes with the most bang for buck as standard & Handles great. Rip out all you don't want and they are light too.