Paw11
Just check if your warranty is covered with the softer springs on the BCs. When I asked they weren't very excited about warranting the shocks with lower spring rates.

Do you end up purchasing with lower spring rates? Did you ask abut warranty or they bought it up?

I ended up going for the Konis. I asked BC (Just Jap) about lower spring rates and they immediately started talking that they didn't think warranty would allow it. If the strut is built right the spring rate shouldn't affect the durability of the shock. If the bump stops aren't strong enough or the shock is length isn't right you can prevent damage by using an overly stiff spring that makes bottoming out unlikely. Adubs have little enough front travel as it is so I wasn't keen on messing with that.I don't know if this is the case with the BCs but it got me wondering enough to go elsewhere.
P

Hey mate,
 
No coilovers for sale here, but just some food for thought: i had cusco springs 4k front and 6k rear with tokico illumina shocks in my standard strut casings, which were good.
 
I have had the BC MH coilovers at the moment, which are the 5/8 as standard. If you don't mind a firmish ride,you may not found them too bad, and with the extra weight of the 3s in the back, i dare say the 8k rear springs in the back will actually ride a lot better than you think. Ever other aw11 owner that i can think of that has said it is too stiff has an n/a, which has a near 20kg lighter gearbox than a gze/3s, let alone the extra weight of the engine ancillaries, or in you case a heavier engine.
 
Your other option would be to speak to barry at manon racing products, they have their own coilovers which they have built to their specs, or are the nz dealer for fortune auto (american coilovers, same price bracket as BC) I believe Phil B is one of the aussie dealers (the guard rolling guy if im not mistaken.)
 
If you were in Vic i would offer to take you for a spin so you could make an informed desicion, if your not in an urgent rush, maybe another forum member could take you for a spin?

Thanks for your feedback and ideas MCT.
I had a look into the inverted versions but I read that the rear damper adjusters are basically impossible to access and they were overall very firm. I live in a semi rural area in Sydney with some bumpy country roads so I might go with the 4/6kg and see how it goes. I know it won't be soft and comfortable but should be better then 5/8kg, the 195-205/50/15 tyres should help with the comfort factor.  
 
I actually contacted Bazda about his MRP coil overs a few weeks ago and he said he didn't have any AW11 ones in stock. He didn't even offer to build any or even how long till they come back into stock. He offered me a set of Yellow-speed coil overs which look like cheap crap.

Paw11
I ended up going for the Konis. I asked BC (Just Jap) about lower spring rates and they immediately started talking that they didn't think warranty would allow it. If the strut is built right the spring rate shouldn't affect the durability of the shock. If the bump stops aren't strong enough or the shock is length isn't right you can prevent damage by using an overly stiff spring that makes bottoming out unlikely. Adubs have little enough front travel as it is so I wasn't keen on messing with that.I don't know if this is the case with the BCs but it got me wondering enough to go elsewhere.
P

Thanks for that. I actually spoke to JustJap about the 4/6kg springs and they didn't mention the warranty thing at all. Just said they will be in my hands about 6-7 days after ordering!
I'll keep it in mind if I decide to go through them though.

Ordered a set of BC BR 4kg front and 6kg rear from Justjap this morning. Should have them in about 7 days as they are a custom order.
Thanks for all the comments/help lads!