If trading forex you are going to need to use DAILY spreads. You mentioned you could not find a good spread. How do you define a good spread. Most define it as a low risk one not realizing they are only increasing their risk and picking a slow spread (meaning the price moves slowly). The wides tFX spreads are the daily they open at 6 pm and go to 3 PM and are usually at most a few ticks off the underlying market in most market conditions. Just choose your fx pair and choose NTM for near the market on the Nadex spread scanner.
I think the first thing is to work on misconeptions of spreads as we really need to define what you mean by can't find a good spread.
Next thing is how to quickly find the spread you want.
If your trading the london open your most likely looking for some decent moves. These FX sdpreads like GBP/USD and even NQ should be plenty fast enough to trade at night.
2 to 5 AM is usually when the best moves happen (Central Time)
Be prepared for all trend chop and swing as you never know what the day will bring. It is even more important to use a wider spread on the smaller trader like chop and swing as you need a fast spread. People try to save money on the small spreads only to be costing themselves from making ticks when the market moves as they move slower and are more sensitive to high IV.
The trades work the same whether your trading the london open or the us open there is no difference dont let the "time" get you. There is plenty of movevent often even better movement during londdons session than the US session as of late.