You can buy a handheld GPS off the shelves with an accuracy of less than a metre.I have no idea how much it goes for but you can start with aviation equipment shops at Wilson,Nairobi.

A good smart phone can do you a good job as far as conversion is concerned.Go to the Maps application and it converts for you automatically.Your desktop can do it for you also by loading google maps website and inputn the coordinates.

For instance,wat u asked is 1°08'05.0"S 37°58'57.9"E according to my phone

I also have a smart phone, is there application to be downloaded for conversion or what do I type in the google map?

@Okonkwo i can deliver them to your doorstep if in Nairobi
Garmin eTrex 20 (High sensitivity gps receiver)@30,000
Garmin eTrex 30 (High sensitivity gps receiver) @38,000
You can have data in any format you want and they are good for outdoor activity and finding your way out. Comes with a preloaded map and definetely I will be in hand to give training on best practices

For question no.2, coordinates in decimal can be manually converted to minutes by multiplying the fractional parts by 60, if the result of this is a whole number(minutes) + fraction(second) combination,treat the fractional part of this result independently and multiply by 60 to get the coordinate seconds, vice-versa holds. (South and West are negative.) Why bother though.

Bought eTrex 20 at 25,000/= some 2 years go. The seller is an authorised dealer for Garmin. The shop is called Titan Avionics and its at Wilson Airport.
You can also buy from Ebrahim Elecronics on Kimathi Street but they are slightly expensive.

As for the units, you can change it from the phone settings of the GPS application.
The GPS can also measure areas in units of your choice(acres, hectares etc).
Now that you mention issue of beacons, surveyors love to use UTM instead of decimal degrees. Something else, using different Datum eg WGS 1984, ARC 1960 etc can give different coordinates.