GBB Pistol Slide Question

[ap27]

I'm looking for a metal slide to replace the stock slide on my TM 18c in the near future. I was looking over all the aftermarket ones on offer and wanted some input on the build of the slides.I understand that having a heavier slide will lower my ROF and basically make it harder for the gun to fire unless I invest into valve/spring upgrades.

So far I've found aftermarket slides that are made from:

Steel (made by Guarder, and are ridiculously expensive!)
CNC Aluminum (Guarder and Shooters Design)
Billet Aluminum (PGC, dont know if its different from CNC'ed aluminum...Is it?)


I'm pretty sure the steel slide would be heavier than the aluminum ones. But will the aluminum ones work well without any other upgrades on propane? If not, any suggestions on what other upgrades I should invest in at the same time?
I don't really care for the heft. I want a lightweight metal slide that wont affect the ROF as much and can work with stock or slightly modified internals.

[Styrak]

Generally you don't need anything else if you're swapping to an aluminum slide. You might want a stiffer recoil spring, since it might be sluggish on the return with the stock spring.
I even use an upgraded recoil spring with my stock plastic slide on my TM Hicapa, because I like the snappiness.

[six4]

Since you have an actual working 18c ( rare in these parts ) I wouldn't change a thing.