You may have a problem if you want it to be nice.
There are a lot of predominantly Thai areas but they are primarily either older town houses or run down and insecure housing estates.
I would not trust living in most of the town houses you have no idea what neighbours you will get or security.
Many places have barred windows. The housing estates i have seen that are more thai are very poorly maintained.
Look along soi 102 about and the Sois off it, about 3km out.
If you want to be close to the beach you need to look around the area into Khao Takiab. Right at the end not far from the temple. Past the turning point for the SongThaews
That is an area i remember that may meet what you want. I looked at a couple of houses there that were not bad, but we chose a beautiful peaceful and well maintained village 3km out that does have many falangs but it is Thai run..
Your best bet may be to get a condo, but condo prices in my opinion are relatively more expensive.
Maybe look at cha-am if you want to be away from people.
If you want thais, then be prepared to put up with the potential noise.
The so called Ghetto area is mainly around the Hilton which gets crowded with older people. That is not representative of Hua Hin. There are some of the bar areas such as soi 88 and 94 also frequented by a lot of older falangs but many places in Thailand have similar.
When i go into town on soi 88 there are very few falang places until you get into town. But, very few places to think of living.
Some people may think that Market Village is crowded with older falangs but that is not the case, unless that is all you want to identify.
The restaurant on the pier that we go to often is adjacent to the Hilton "Ghetto area". It often has just as many thais or younger tourists as there are older tourists. It can hardly be declared a ghetto.