6″ Angle Grinder ~ Exceeds Wire Wheel RPM?

Hi! I’m doing a lot of superficial rust removal from 2 1/2″ x 1 1/2″ rectangular steel tubing. I’ve been using my DeWalt 4 1/2″ DW402 7.5 amp angle grinder with a 5″ wire wheel on it but it’s old and bogging down so I’m in the market for a new angle grinder. Also, It seems that the RPM on the angle grinder exceeds the RPM on any wire wheel that I’ve been able to find. . .seems most wire wheels are made for Bench Grinders with lower RPM?

Since I’m doing so much grinding/wire wheeling, I’d like to step up to a higher amp and larger angle grinder to help speed up the process and also step up to a larger wire wheel. .6″ or 7″.

What are my options for wire wheels for a larger angle grinder?

Thanks in advance!