The best TIP to go with the MSCAI (see sig below) or with any intake, IMHO, is the stock one. It is free. It does not need to be installed. There is no good evidence that any of the aftermarket TIP's actually produce any more power. Despite its odd shape, the stock TIP seems to flow at a higher air mass rate than the turbo is capable of handling, so one that "flows better" will not produce any measurable gain.
So, for appearances or bragging rights go with the TIP that you think best suits your personal preference. Until I see before and after dyno runs showing a gain, I'll put my money where true power can be made.
And don't tell me that the stock one leaks. They all will leak if you let the clamps get loose. I'm at 38,000 miles and with my mods am holding 18 psi in the higher gears to my shift point, 5,500-5,800 rpm.
Same thing with the stock BPV. Works like a charm. Holds boost great.
13.4 quarters at 106 on stock tires. 40-120 12.5 seconds.
The intake restrictions are in the stock air box, not aft of the MAF. The exhaust restrictions are upstream of the stock CBE. The stock BPV does not leak any more frequently than any of the aftermarket ones. Mods that help other cars do not necessarily produce more power on this platform. Target the known weaknesses.
If it ain't broke, don't fix it!