I suggest asking or posting an ISO for it.  
Being a newbie many will not discuss services however if your request pertains to attire, if the person sees coupled, requests regarding hair/nails/grooming or any other non-sexual thing go ahead and ask or post.  

Hopefully, you're choosing a well-reviewed lady

and can read the reviews to get an idea of what's available, her P411 profile if she has one (it allows ladies to list intimate activities they enjoy) and after you're screened, she may entertain your more specific question.  However, some ladies will not discuss details even after screening.  Tread lightly & follow her lead.

Best of luck

If someone fills out my contact form via my site, in full, with a ref i can check, then they are allowed to speak freely with them. I appreciate knowing exactly what someone is hoping to experience with me before we meet.

xo
LaRue

I feel it is very appropriate to discuss your desires. I do request that the language remain PG rated during the emails but I think most requests can be communicated in that manner.

you should be reading the "juicy" details of the review and looking at her profile. I like a pretty broad menu and I never ask any questions, I simply read the juicy details of the reviews and find out if the escort offers what I'm looking for. Since you said "What I'm looking for is not too weird" you should be able to determine if the escort offers what you desire.  Of course you have to be VIP to get the juicy details.  

Thanks to everyone who replied.  
My next question is about getting "screened".  For a date in Vegas, if everything I wanted would be in public (nothing lewd or illegal in ANY way), would I still need to get screened?  There would be no meeting in a hotel room...no going anywhere private at all.  I have a feeling that what I am looking for is pretty mild in the scheme of things.
Thanks again for sharing your thoughts.