Soft turn on for old color unit for color??

[vintagecollect]

I know variacs are good for gradually turning on older color sets to protect caps. Has anyone devised a solid state soft turn on device for these that can handle 350 to 500 watts needed power handling for old color. Please post info. if available, I really want several of these as just simply turning on a roundie, knowing it's surge current protected every time , be a would be a nice setup without having to fiddle with a variac, cleaner too. A nice power up time would be gradual 0 to 120 volts AC over a time period over several minutes. Variacs are also getting hard to find & expensive. Please post insight on subject.