Lookind for info on SDIRA Providers

of the following SDIRA providers:

• AccuPlan Benefits Services
• Broad Financial
• IRA Financial Group
• MySolo401k.net
• Sense Financial

does anyone have any experience they can share? i.e.

• Do they have an online platform? Is it easy to use?
• Do they have flat fees, annual, per-check-written?
• etc.

Their websites often super vague and seem like they just want to waste my time over a phone call.

Background:

I have an old IRA from a previous employer that has been sitting around gathering dust and hemorrhaging money via fees since I left my old job some time ago. There was also a piece that John Oliver did a while ago that really got me thinking about what I can do with it myself.

I searched through r/investing yesterday and didn't really find any specific stories about actual SDIRA providers. I want to use the IRA to purchase cryptocurrency, real estate, and possibly to start a business. I read about SDIRAs on investopedia, particularly the prohibited transactions and think I'm fine there. I am hoping someone here can tell me which of those would allow me to best do that with minimal overhead.