Restringing costs £20+ (at least it does where I am), so you’re best off getting something new.
new rackets aren’t necessarily likely to have decent strings in, nor string which will last a while – a bit like new bikes have cheap chains on.
Rackets can behave very differently according to the strings and the stringing tensions, so borrowing someones and being impressed by it might not guarantee that it will feel the same once you break the strings and have it restrung – which can be quite often once you start hitting the ball well.
So you want to look for a midrange racket with a good swing-weight and gripsize for you. The wider the frame (perpendicular to the strings) the stiffer the frame, and the more ‘power’ the racket can give you.
As a bloke you may not want a wide racket as you have the strength to hit the ball hard anyway – notice how people like Federer favor a fairly slim Wilson, as did Edberg, Sampras and others), and the female pros tend to go for wider rackets that do a lot of the work for them (apart from control).
See if there is someone decent at your local club that can offer advice – they may have some old rackets they might sell you cheap and they may also do restrings cheap.
Or see if there is someone who does the restrings for people at the club – they might be able to source rackets cheaply and even lend you some to try – and they will be a good contact for future restrings.
Or are you anywhere this outfit?
http://www.pwptennis.com/
they often have decent deals plus reasonable prices on stringing.
you will need restrings in the future so finding someone of reasonable cost will be good, who can also advise you on what strings are robust (I haven’t played for a long while but would break synthetic gut in 3 days in a graphite racket compared something like pro-blend (half kevlar) which would last 3 months).
Otherwise a midrange graphite Wilson might well be a good starting point – but nothing too wide or extreme – like the old Wilson Hammer.