Sorry gang, have been in Maryborough at the 24 hour Energy Breakthrough race with the students from school. Am wrecked now!
Tamiya hop-ups. You're right, you don't 'have' to buy tamiya ones now (in the past they HAD to be Tamiya) but to be honest, the Tamiya ones are ALWAYS better quality! 3Racing make a few bits and they 'might' be ok, but I've learnt over the years and now I simply buy the Tamiya ones the first time and be done with it. I think Scott has a 3Racing alloy front shock tower or something on his car? I went with the Tamiya Carbon front end on the last car just cos I could. Seems to be good so far.
In terms of replacement shocks - you really can't go past the TRF M-Chassis ones. They are pricey though $70-80 I think. The Mini C.V.A Shocks are good too though - #50746 I think they are. There should be a build doc on RC-MINI somewhere that tells you to build them to 56mm length for best handling. They use spacers to set the ride height whereas the Tamiya TRF ones have a threaded collar that makes it infinitely adjustable.
That HPI shell is some serious vintage stuff! They were a great shell for racing! The Monster Mini's are probably the coolest 'realish' looking mini (unless you want a BINI - but I don't imagine that'd be the case around this forum!) They are pricey though unfortunately.

There are plenty of other non-mini related bodies though available too - rmart.com probably has the best selection in the one place.