I heard there's this chain called Mode-off part if the hard-off group of second hand shops. They carry all sorts of crap and probably gems. All items are pretty arbitarilly priced and usuall for a few bobs only.
Others may disagree, but I'm not fussed. I mean there's absolutely no way you can hide point collars and they've been worn with suits without fuss for god knows how long. But if you are uncomfortable, then stick with full cutaway or semis with collar length longer than 3" That should be sufficient..I wear 2.5" semis because that's all TM Lewin does now days and I don't mind and no one around me minds.
I have a white, curved cut-away, french placket in royal oxford. Have to say that I highly recommend you not to get curved collar if you intend to not wear a tie. The collar looks very awkward unbuttoned. I say curved cut-away is best with a bow tie.I prefer a semi or full cutaway for no tie. Semi is the safe option and full tend to look more upright.