My PC, recently upgraded but still old hat with a spec similar to yours, runs Skype very well even with a fairly low line speed of 2 - 2.5 Mbs. It's a great service for what it costs !
The Cell Phones in the US seem very odd to a Brit. I had a PAYG when I lived in Seattle for a few Months, it was tied to a network and not cheap. For a basic Clam Shell 'phone it cost me about USD 120 and I don't think that even included any air time. I was also amazed to find that minutes were deducted for incoming calls, seems they want it both ways.
I was in Hawaii a couple of years ago for a holiday and paid about USD 40 for a very basic 'phone with 200 minutes on board, I was surprised to see the minutes disappearing fast until I remembered that I was also being charged for incoming calls.
Here in the UK I have " Network Free " 'phones which work well for me. The one I use now is a Dual Sim machine, a cheap and nasty Chinese copy of a Blackbury, but it does the job OK. The reason I went for a Dual Sim is that the Mobile Number that I have had for years is on a fairly expensive provider so I use the second SIM on a cheaper provider to make most calls and leave my original one for incoming calls. Works well but does confuse people when I call using the second SIM and they see an unrecognised number !
I don't have a plan, just Top Up when I need to, either on line or by buying a voucher from almost any shop, very easy. My main number has no restrictions at all, just keeps running on and is not cancelled whether or not I use it. The other providers only stipulation is that I make or receive a call once in three Months. SIM free 'phones here are very cheap, starting at less than £10 and if, like me, you don't care about " image " that's the way to go. My current Chinese piece of carp is supposed to be all singing and dancing with MMS and Internet access but I tried sending a picture once and it didn't work, really disappointed - I don't think ! Never even tried to get on to the internet with it, just not interested !
The no 'phone using whilst driving has been in force here for a few years and a good thing too.Of course people still do it, even texting whilst driving
but the penalties if caught are fairly stiff and it is an " absolute " offence, no excuses at all accepted and no warning, straight to a Fine of I think £60 and three points on your licence. ( 12 accumulated points put you back to wearing out your shoe leather for a few Months. )
You can use " Hands Free " technology so I can see why, if you must use the 'phone whilst driving, why no excuses are accepted, there is a cheap ish solution available and of course most newer Cars come with Bluetooth already installed.