Yeah, 150 is aight.
If I read your post right though it seems that you are running a stock head?
If thats the case, you should consider getting a 70cc hi comp head.
Its a squish thing.
You might not see much, if any, more compression, but I would get one. They are pretty cheap.
More compression=more heat=more wear on your parts.
In some cases its worth it to have like crazy hi compression. If you are just running it as a daily rider though 150 is plenty.