After building a Garrard 301 set up, i.e. plinth, rebuild of table, tone arm, etc. I'd say take your time and look for a reputable arm that fits many modern carts compliance.
Personally I'd stay away from vintage arms if your going to run modern carts just my experience. Also find one that has easy set up and preferably with on the fly adjustments of VTA etc. A well engineered tone arm will make your task much easier to implement correctly.
Oh one last thing, not sure if your flush mounted your Garrard into the plinth or left it on top. but take the height in to account for the tone arm and mounting arrangement, that can make or break the set up. The mounting arrangement can be a pain and you want it to be easy to use and adjust for your tonearm and future tonearms. Cable run taken into account well.