I don't there is all that much you can do to an EFI performance wise but do a search in this thread and you might find something. Welcome aboard by the way.
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Colin
2000 PSD F250XLT Ext cab, SB, 4X2, Zoodad, ccv, Kwik filter W/Pete's cover , 4" turbo back flo-pro ss exhaust, fog lights & box cover
1967 Mercury F500 330, 2 spd axle 8 x 12 box & hoist
1978 F100 Custom 300 I6 (fresh), 4spd std (rebuilt) new hubcaps.
The EFI engines take a little more work to mod than the carbed engines, simply because of dealings with computers and electronics. There are ways to do it, and there are some on here that deal with EFI performance, so do some searches with the search feature and see what comes up.
As for turboing the EFI, check the turbo forum, or check out Ford Six for more information, especially for turbo work. There's quite a lot of people who've turboed the 300 on that site with success.
If, however, you're really looking into performance, you might want to go with a carbed engine, as they are much easier to modify/upgrade/turbo etc...