@Chopper is the one on this.
I used this: The D.I.Y Thread - #38 by Chopper
It works great. Could do with being a touch thinner because the wheels catch it a bit on slides so might want to have a look on that site for slightly narrower strips. So maybe 30mm x 30mm or lower.
I think that one in the link is good because you have a good area to drill your screws in.
It’s not a huge problem though if you skate properly.
You can get it cut to length too from there.