I am extremely mean, so does anyone know if there's any alternative to main dealers for a new MAP sensor, other than Hardtop Guy (don't really want to wait for delivery from the US)?

 

Try CFL Honda in the US. I think it was just over a week for my stuff to arrive

 

and they are cheap!!

 

I'm pretty sure the majority of MAP sensors are interchangeable, worth having a check and then a quick browse on Ebay..

 

I can sell you my second hand one asI replaced mine with an omni sensor as I needed to read higher boost. PM me an offer if interested

For a standard ECU I don't think you can replace the map sensor with anything other than a Honda one as a) the output voltages will most likely be different so your ECU will not be able to provide the correct amount of fuel / timing and b) there are virtually none that actually will physically fit, omni may do an OEM replacement but you are almost certainly looking at importing from the USA if they do