Hi Steve,
Unfortunately, the two guys who have probably done the most development work on their Golds don't come on the forum these days. I'm thinking of Peter Hill, who hill-climbed his Gold convertible and Adrian Lee who track days his. Peter Hill would probably have been the most helpful/relevant, but he sold his car some years back and I don't have any contact details for him now.
I think that fitting better bushes to keep the front alignment under tighter control is a good first step. You probably need more suspension compliance for hill-climbing than you would for circuit racing, so polyurethane bushes rather than nylon are more suitable. Having said that, the standard MG Metro ARB to subframe bushes are nylon, so I would fit a good pair of them and then use the poly bushes for the ARB to lower arm joint.
Also at the front I would fit road spec Metro adjustable dampers rather than race spec ones. I have used AVO front dampers and found that for road use the lowest settings give the best results. The standard Metro Hydragas units already have some internal damping so the telescopic unit is adding to that. The main thing to watch with fitting front dampers to a Midas Gold is to make sure that the suspension bottoms out on the top arm bump stop and not on the damper, otherwise the damper top will push its way through the wheel arch eventually.
For the front hydragas you could look at doing the Nitrogen valve mod. I am now set up to do that with a bottle of Nitrogen gas and a high pressure gas regulator that came from the US. I've modified a pair of front units, but as yet I have not fitted them to a car thanks to having too many other distractions.
At the back I would just make sure that everything is good and tight. A slightly worn rear radius arm bearing that might scrape through an MOT is going to make the back end feel loose when cornering hard.
I have also come across cars that rely purely on the mountings at the front of the subframe, which can't be too good for cornering either so I would start by checking everything over and making sure the subframes are secure too.
When we met you at Wiscombe Park last September I noticed that your competitor in the GTM was running AVON ZZR tyres in 185/55 - 13. As these are road legal track tyres they would seem a sensible start, especially as that is what your competitor is running. I found one website selling them
http://bmtrracing.com/size-price-list/ - they are at the start of the last section for Road Legal Competition tyres. There are two options available so it would pay to ask the supplier what the difference is, though I would guess one has a softer compound which would be more suited to hill-climbs and sprints.
I look forward to hearing how you progress with your car and hopefully I can get along to see you in action again at some point this year.
Regards,
Alistair