We went to the Calypso back in 2006.
The hotel isn't too far from shops.
Turn left out of hotel and take second left and you'll find a small Supermarket. Prices not bad and a fairly decent range of food plus British food. Fresh food etc. (sounds like the same place as alsbaby described)
From memory water was fairly cheap.
We had originally booked two rooms as Thomson said that they couldn't provide connecting rooms.Emailed the hotel who advised me to email back about 2 weeks prior to departing (They don't get details of bookings until then). Did email and we got a lovely family room. (Probably saved the hotel some money as well, but we were happy).
Top tip - book the fridge to keep your cold drinks cold.
To walk to the main street of shops/ bars etc you turn left out of the hotel and first left. It is about 5 mins to the main road and then about 5/10 mins down the road to the main part of town.
To be honest, the biggest problem with the Calypso would be the guests, the other Brits that are staying. To be honest all 3* Spanish hotels are likely to "suffer" from the same problems.
We've stayed in Salou 5 times now - and the wife prefers the Avienda suites. Personally I prefered the Caribe Resort (if you have the money and want to get away from the British)
Any other way we can help, let me know.