Which Motor for new Nitro Sport 188

[Looking4Lakes]

I'm plan to purchase a new Nitro Sport 188 (Fish and Ski) this season. The Motor options are as follows, with their associated prices<br />Mercury 115 ELPTO $18,395.00 +$0.00 (Base)<br />Mercury 125 ELPTO $18,975.00 +$580.00 <br />Mercury 115 EFI4-STR $20,235.00 +$1,840.00 <br />Mercury 150 XR6 $20,900.00 +$2,505.00 <br />Mercury 150 EFI $23,420.00 +$5,025.00 <br />Mercury 135 OptiMax $24,060.00 +$5,665.00 <br />Mercury 150 OptiMax $26,130.00 +$7,735.00 <br /><br />I'm looking for some advice and/or recommendations of these motor options. Their web site has stats and motor technology speak which goes a bit over my head. <br /><br />Any advise from those of you who are experienced with motors would be appreciated. Would YOU spend the extra money for these motor upgrades?<br /><br />Thanks in advance