How should I modify/improve my STS ?

[clubby]

It's a good question though, hopefully some wise folk will be along to share their wisdom.

No need, you are quite right.
STS 2 originally came with Judy C Long Travel (!) 80mm . (White with blue decals) - Still have mine but needs new elastomers or springs.

Run my pace forks at 100mm though, have done since they were fitted in 1998 and never had a problem.