I can share some thoughts as I currently live in one of the condos
you listed (Riverine) and also work in the Suntec area. Keep in mind that I've only been in Singapore for 3 years and some of my observations could be wrong. First of all, not many condo
s that gives 2000sf of living space for a 4 bedroom. The square footage advertised on the property
sites includes balcony space, and some could be quite misleading. Some bedrooms could be very small too - may not fit a US queen size bed. Also the distance to MRT station advertised on . can be misleading. Best thing to do is to see it yourself when you are in town.
As regards to Riverine, it is a nice condo with all the standard condo facilities (gym, pool), also has private elevator which I find quite convenient. You should be able to get a 4 bedroom here within your budget as the rental market is slow now. Each condo does come with a maid room (really a storage room) and a tiny bathroom for maid. Depending on which side your condo is on, the view is fantastic - you can see the new stadium, Kallang River, Marina Bay, Singapore Flyer, Suntec etc. It's easy for public transportation with 2 bus stations within 5 min walk, and 2 MRT stations within 10 min walk where you can also find super markets and eateries. Both of the MRT are on the green line, which could be a downside depending on where you want to go. The condo is a bit "lonely" in Singapore standard - it's next to the river and the park all by itself. The residents in the building are probably a third or half Caucasian. Due to the proximity to Geylang, some consider the surrounding area unsafe at night. However I think the "unsafe" in Singapore standard is relatively safe in US standard.
For you to go to work from Riverine, you can take the bus or MRT -it's a shorter walk to the bus station, but you'll have to walk from Beach Road cross a bridge to get into Suntec. Fastest way with the MRT will be getting off at City Hall (3 or 4 stops depending on you get on at lavender or Kallang) and walk the underground passage to Suntec. Both will require 5-10 min walking and takes about the same amount of time (I'd say 30 min max). The green line could be quite crowded in the morning though if you hit the rush hour.
Suntec is a very accessible location so transportation won't be a problem for you wherever you choose to live. There are also restaurants, shops, supermarkets, movie theatre right in Suntec City Mall and the connecting Marina Square Mall.
Hope I answered some of your questions.