Not really any serious power gains to be had, nothing of serious consequence anyway.
New map, few more hp (some claim 200kw doable, I think thats likely BS)
Decent headers, pickings are slim for RHD, brintech in aussie seem to have the best option but its not cheap, however dyno proven 13-15kw https://www.brintechcustoms.com.au/all-products/n52-custom-exhaust-headers
MILVs, modifying the intake lift of the valvetronic system, gives a solid bump throughout rev range but requires a custom dyno tune. There is also a custom exhaust camshaft out there, but its currently vapourware. https://www.bimmermilvs.com/
Thats about it, at least sanely. Lower spec N52s benefit from bolting the HO N52B30 bits too them, but the 130s come out of the box in the highest state of factory N52 tune.
There are some epic N52B30s out there in racecars, Kevin from Birds has/had a 380bhp N52B30 that runs S54 ITBs and custom cams with locked valvetronic... but ya talking $20-30k. There is also BPC who have played with multiple silly power turbo N52s, but they're hand grenades so are not available to purchase as kits.
As Dave says, best option with 130s is fixing the suspension and putting an LSD in... Ive done some very spirited B road blitzes and Ive never thought afterwards "I need more power ".. near 190kw in a little hatch is pretty solid out of the box.
If your 130 is feeling slow, likely something needs some love. A service, new airfilter, new plugs, cleaning out any intake manifold slime and then resetting the DME adaptations with 98 in the tank is probably a good first step.