I've tried variations of squats and tried mixing the squat section of different training programs with the 5x5.

I've tried: back squats without a squat rack, but got to a weight where i couldn't power clean it anymore.
I've tried: 1x20 back squats from squats and milk with back squats, got to a weight where i couldn't power clean it anymore.
I've tried: 5x5 with hack squats, got to a weight where i found it easy but couldn't add on anymore weight due to not having heavy enough plates, and no money to buy new ones.
I've tried: Steinborn Lift many times, cant hack it.

Basically I moved house, had to get rid of squat rack - no space , no money for gym.

Now the only thing i can think of are weighted pistols. One legged squats must be hard, and it will be a while till i can add weight. I'll start with a fairly high box, then get lower ones as my strength prgresses. Once i can add weight i could wear a rucksack and fill it up with plates to make it more challenging. This should be pretty hard shouldnt it?

If i could do this in place of back squats. should i continue doing it with 5x5?

Also, will doing pistols increase my running speed, or just give me more power?

I can't answer your question but just wanted to say, some places like 24 Hour Fitness offer memberships for around $30 a month with little or no initiation fee. I don't know how bad your money situation is but if you have a few dollars to spare you should check the membership costs of gyms in your area, you might be surprised.

Do pistols onto a low, low box/step, whatever.
Do them onto that like box squats!
Pistols are great.

You hold onto a dumbell.

Cheers for the advice lads.