I can't really help with suggesting wheelchair accessible hotels, but as far as walk in showers are concerned most showers I have seen in Goa have just been wet rooms so that should be OK I guess.
Perhaps others have more info.
Strangely enough, I commented to my wife this year that there were a lot more wheelchairs around than previously, so whilst I won't say that it will be easy it certainly is doable.
Good luck with your search

thank you del949 for your reply wet rooms are perfect I can manage a couple of steps and a very short walk with my sticks so would you say it would be easy for us to get around I also need a hotel that has either a slope or steps going into the pool rather than ladder steps

Try Silver Sands in Candolim, they have little bungalows great for easy access, the showers are wet rooms. You are a literally a stones throw away from the beach, whilst there are many restaurants, shops etc just around the corner on Beach Road.
Have a lovely holiday.

Today in Sunday edition big advt.published in newspapers for this resort,looks nice in website though I have not stayed there yet.
http://www.aguadaanchorage.com/

Siver sands would fit the bill except for the pool. I think you need to up 5-6 steps to get to the pool and then into the pool is a ladder
I can't think of any that have ramps etc rather than ladders.
Access to the silver sands is via a tarmaced road without steps (maybe one?) and you can reach most of the restaurants from there without going "off road"
The silver sands has rooms on only two levels, I guess about 15 steps to upper floor.
The bungalows are all ground floor, a bit small and a bit dark IMO but really good for sitting out and people watching as everyone has to pass your balcony.
Beach access from there shouldn't be a problem for you either walking or I think that you could even get to the first shacks via a wheelchair.as the proper road goes almost all the way to the shacks
However, if the chair was a problem I am certain that if you asked at one of the shacks they would send a couple of boys to help you
.AFAIK the silver sands is ONLY available via a tour operator not by booking direct so you would need to specify goriund floor when booking unless of course you select a bungalow.
Note the silver sands is not the same hotel as the silver sands hideaway.
I can't advise on such as Highland Beach as have never taken a lot of notice there nor other resorts.
The Phoenix Park may give problems as the entrance is up a few steps amd there are less ground floor rooms there.
although "I think" the pool has steps.

Getting around?
Not sure, as I said there were more wheelchairs in Candolim this year but I have no idea of the persons disablities etc.
Certainly in Candolim using the Silver sands as a base you would be able to get around the immediate area with no problems as the road is busy at times but not excessively so and is flat.
Venturing further afield, i.e. the main Calangute/Candolim Rd will be doable but quite worrying as pavements are poor, uneven and intermittent which may mean taking the wheelchair along the edge of the road.
This road IS busy. Should you decide OK, I would advise maybe a good torch or flashing bicycle lamps etc to let road users know you are there.
The wheelchair users I did see seemed to be given a bit of courtesy and assistance in crossing roads etc.
Also, travelling a bit further afield the taxis are cheap and will get you to most places, advising where you won't be able to manage etc.
You will have NO chance of using local buses with a chair .
Hope I haven't put you off but don't want to tell you "all is fine" only for you to find it isn't.
The Goans will really try to assist you in any problems you may have...honestly
Unless you are a very nervous person I think that you would cope OK and enjoy yourself...... if you don't try you won't know

thanks guys for all your replies they have been most helpful