My advice is to buy the VDO hose and dual sender.  If you want buy the
gauge later just hook up the idiot light wire to the sender and wait.
I'd stick with the VDO set up since they have the proper hose and dual
sender for this application.  Not cheap, but it fits and will last.
Here is one source (where I got mine):
http://www.bus-boys.com/bbvdo.htm

I am not a fan of tees or metal piping attached to engines, too much
heat and vibration.  Eventually they will crack and fail.

I have pix of my installation if you are interested.

--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Daily driver since 1969)
'74 MGB GT (Restoring sloooowly)

Personal mechanic for:
'70 MGB GT (Daughter's)

Assisting on Restoration (and spending OPM):
'72 MGB GT (Was daughter's, now son's)
'64 MGB (Son's)

Stripped and gone but their parts live on:
'68 MGB, '73 MGB, '67 MGB GT