Tennis Clothing Source

Ziel:

keep the K Four.
if possible you could add some info whether you play baseline or attack the net.
try to demo both candidates.
if possible try the Metallix 4 with Head Synthetic Gut 18 (yes 18) at 55 lbs, while the K Five 98 with Wilson K Gut 17 at 52 lbs. ask the shop keeper if it is possible (you need to pay for the strings and stringing service though).
during the demo, hit some strokes with your current K Four first. then with K Five 98, then with the Metallix. you will find which racquet suits your style. if you're a baseliner, maybe you'll love K Five more. btw, K Five (98 and 108) is the most comfortable racquet from Wilson K Factor lines – ever. attacker might find the lighter Metallix is very maneuverable at the net. you will love the stability of Metallix when countering heavy strokes at the net with your volley, even if you hit it off-center,
about the strings: who wants to live forever? assuming you played tennis for some times, now is the time to really feel. 17 and 18 gauge strings are the most lively ones. who knows, maybe you don't spin that heavy – so you won't break strings too often. but if you do break them, restring with same gauge. why bargain feel to durability? spend more on your favorite sports oh, boy. Head Synthetic Guts are not that expensive, right? you can even put Head string on K Five if you want to.
hope it helps and good luck finding your racquets