Most semi slicks (a050, r888, v70a etc) are street legal. Some like the Hoosiers that Glenn was running aren't because they're basically a slick with 2 grooves in it, even though they are dot approved and street legal in america. But you're not interested in semi slicks anyway so never mind.

Any of the tyres Tree mentioned are exactly what you're after. Best performance before stepping into semi slicks and they'll keep you in the unmodified class. They're grippier and hold up to track abuse much better than regular street tyres. Toyo t1r are just regular high performance tyres and are much less suited to track work than the tyres on Tree's list.

Toyo T1R's are a great street tyre, I've been using them on MR2's for years. Can't comment on their track performance, but you'll get much less life if you go for a semi-slick.
Unfortunately the appropriate sizes seem to have disappeared from the Toyo AU website. (!!)
My last set were ordered from the UK (http://www.demon-tweeks.co.uk), arrived to-the-door within 5 working days, at no more than cost price in Australia, including shipping!
Go 205/55 and 225/50. 

Tree
Staying true to the street class I would recommend these if they come in your sizes:
Advan AD08, AD08R
Hankook RS-3
Bridgestone RE-11
Toyo R1R
Dunlop Direzzas
Nitto NT05
Kumho KU36s although the Federal RSRs have taken over those for the "it" tyre being cheaper and faster
 
Also double check the treadwear rating to make sure it's still within your class...

Couldnt have said it better myself Tree! (Federals RSR's - bang for buck....cant beat em IMO).

Unfortunately they don't do RSR's in stock sizes, Toyo R1R's might be the best bet i think...

I remember calling up about the Toyo T1R's. Although they are not listed on the web, call up your local tyre dealership, they can still probably get them in.
 
I only ran them on the rear's and found at high speed they felt horridly floating, even with rock hard suspension. They clearly have a soft sidewall - All of this has been discussed previously on the forum.
 
I gave up on tyre selection and bought some second hand forged lightweight 17' jap rims to get a better tyre selection. Wheels weigh about the same as the 15' rims and I can get a wider tyre on. Win-Win!

"Tyre recommendation for 15 inch wheels"
Problem is getting the right size for the rears.
 
A Google search turned up these, anyone tried them?
http://www.jaxquickfit.com.au/tyres/brands/pirelli/p-zero-asimmetrico
205/50R15 and the scarce 225/50R15 size are listed
BTW treadwear 220
 

I use "Nitto Neo Gen" they wear really well for a all rounder, check them out on you tube

Toyo R1R are good but will tend to overheat quicker than the others due to the tread design. The small tread blocks move around much more and will overheat and start wearing down quicker at the track. Would be good for wet though.

Tree
Staying true to the street class I would recommend these if they come in your sizes:
Advan AD08, AD08R  Only available in 195 & 205 15" 50 series
Hankook RS-3           No 15" available
Bridgestone RE-11     No 15" available
Toyo R1R                  Only available in 205 15" 50 series
Dunlop Direzzas         Only available in 195 15" 50 series
Nitto NT05                Only available in 205 15" 50 series
Kumho KU36s Only 205's although the Federal RSRs Only 195&205's have taken over those for the "it" tyre being cheaper and faster

 
I've been doing some more research, and as you can see from my notes in red, it looks like it's almost impossible to get decent tyres for the oem sizes required for the unmodified street class :(
I guess i'll have to get some 17" wheels and go into the street modified class and try to keep up with Adrian lol...
 

Hi Rick,
 
I will have a set of 16' Enkeis available if your are after other wheels.  Not 17's but good light wheels.
 
I just purchased another set of 17s.