Hello I am looking to buy a 21' Four Winns 215sd 5.0 mercruiser 220hp volvo gxi outdrive. What am i gonna get out of this boat, looking to tube and cruise around 30-40mph...they are asking 15,000 also. I'm not a wrencher, pretty much gonna take friends out to the islands and hang out... Is this the boat for me,Oh also wanna know if i should have trim tabs installed???