For Terra Nova; Zephyros model is the budget version of their Laser Comp model (bit heavier and cheaper due to less nice materials used). Laser Comp design is a tight fit for one let alone two, made for being lightweight rather than roomy. Build quality of Terra Nova stuff is very good and they are Derbyshire based, TarpTent are USA. Very similar designs and throw in another maker Hilleberg who are at the top end of build quality and budget.
Terra Nova, TarpTent, Hilliberg are all quality lightweight tent makers. I linked to the Terra Nova sale page because they often have really good deals. The 'Coshee' model looks interesting, but I've never tried it.