Welcome to the club bud
To benefit the most from the ATR inlet manifold you'll also need to upgrade your header and exhaust. There's no point drawing more air into the engine if you can't expel it just as fast. Also if you're going to the effort of the ATR manifold and exhaust, you may as well at least go for the more aggressive a7/a8 cams, otherwise you really will noise little difference.
Also, the success of all those mods put together solely depends on the map, and a map from some random chap in America is very unlikely to make the most of those mods or even work. The P28 is the right ecu for modifying and tuning, but you really should be looking at collaborating it with the likes of Hondata S300 or similar... Not a "chip" that is likely to just adjust your fuelling and vtec point.
None of what I said is cheap though. You're looking at £600-800 for the Hondata and tune, and depending on your mods, a decent exhaust, at least £250, header, at least £300 and cams are about £100 second hand. And you'll see about 210-220 bhp and early 170s torque.