NSFW Image Generation Service

I just started using SillyTavern and Stable Diffusion today, so a little new to this. My 6GB GPU is embarrassingly slow and before I decide to get a new machine, I want to ask a few questions here -

1. Any online service like openrouter for image (paid or unpaid, either works)
2. Is there any setting that I might be missing to speed up?
3. If I decide to buy, what's your recommended GPU?

Thanks