Use PDH API's to get the memory usage, CPU time, VM, Page fault, Threads, Handle count and all other parameters availble in task manager. In this API there is a parameter for machine name give the remote machine and get the result. I dont know all API's now and not having MSDN search on google or MSDN for PDH Happy Coding :)
Get the facts or facts will get you and when you get them, get them right or they will get you wrong. Happy Coding :)