Did you clean the new discs with brake cleaner before fitting?people often forget to clean off the proctetive coating befor fitment . A 4 pot caliper will be a better option then the standard or the tt brake upgrade,less weight and higher braking force.
If they fit then get them,don't worry too much about speedo,as long as you make allowance for your speed then what is the problem ? You will find your speedo maybe out by +/- 5% or so ,check it with a GPS.
I've got the 3 box on my golf,best £300 I've ever spend ! The bore of the Jetex are Bigger then other xzorts ! get the 3 box and if / when the state of tune of your engine require better breathing ( I think you'd need to be making 350bhp+ before) , replace the front box with the straight thro pipe .
what about this : http://cgi.ebay.com/ebaymotors/93-98-VW-GOLF-BLACK-DUAL-HALO-PROJECTOR-HEADLIGHT-MK3_W0QQcmdZViewItemQQcategoryZ33710QQihZ014QQitemZ330181035229QQrdZ1QQsspagenameZWDVW $140 to UK :-(
Talk about octane booster,did anyone see the " Fifth gear "program on "octane booster additives" that you can buy of the selves ? The results was very interesting to say the least,not only No power was gain if anything there was a power lost in every Brand they tested.