is there any 3.75 or 4 inch doctor who figures ?

Good news ryanisawesome124, there is now a line of Doctor Who 3.75 figures.

This is what I have of the size but there is more being released.



there are more classic Daleks being released.

It's no problem. But when it comes to recent versions of the characters, like you said, you'd have better luck in doing customs. But when it comes to Doctors 1-7, some of the companions, some of the enemies and such at the 3.75, Dapol made them (but they may be either hard to find or expensive, be it carded or loose).

Learn something new every day! Good call!

There are, but their vintage had have very limited articulation. A company called Dapol made them, covering the Doctor from 1st to 7th, Daleks, K-9, The Master, a couple of aliens, a couple of the companions and, of course, a TARDIS playset that folds up to look like it does on the outside and unfolds out to have the interior. RedRebelCustoms posted a link that's close, but the Dapol figures are in the same size. Here's the link:

I myself have a 7th Doctor with the grey jacket from the line and played with it when I was younger. He's in the 3.75/4 inch size.

http://doctorwhotoys.net/doctorwhoactionfigures.htm
That link is all the Dr. Who figures. They are on the small side of the 5" scale for the most part. If your intent is collecting there are no 1:18 scale Dr. Who figures from a factory release that I've ever seen. Customs would be your best bet. Hope that helps or at least clears it up.