IDOC,
Most entry level helis available today will get you flying and well on your way. Some just do better then others, some even do so at relatively low prices (e.g. the Hawk IV). It is relatively inexpensive to buy and repair after the odd "mishap". It is easy to build, it comes with a great muffler, it flies well as a trainer and even into more demanding 3D aerobatics, is relatively maintenance free (plug and play) with few "issues" associated with it.
I too love the 50 size (my preference is the Century Falcon SE VII). Though it only costs $400.00, it is a full blown "'Hi-Zoot" heli that even comes with 600mm Fiberglass/Carbon fiber composite blades. If you go that route, spend an extra $20.00 for their 600mm woodies and use those for training, and save the FRP units for later, when you are comfortably into forward flight and aerobatics.
My choices in entry level radios are the Airtronics 6000 Super or the Hi-Tech Eclipse 7. If you can afford a bit more then the hands down choice is the new Futaba 9C.
Gyros, whatever you go for, match it to a digital servo if you have the budget. Then it will take you well into any flight arena you will progress into. In entry level I would suggest the Century PG-2000, up from there is the Futaba GY-240 and up from there the Futaba GY-401. They will all work with a standard servo, but a digital makes all three work 2 to 3 times better. If your budget allows, get the GY-401/9253 combo (About $220.00) right from the beginning.
Engine - stay with OS. Engine-Stay with OS....Engine Stay with OS...I guess you get the picture re: engine.<G>
For more info on various issues with various heli models check out the owner reports in the showcase forum area of
www.rchelicopters.org and the brand specific forums here and on
www.runryder.com
Whatever you start with I am sure your will find this a very entertaining passtime. Have Fun.