Brother Vti is 1.6L 130PS at 6,600 RPM & Exi is 1.5L 110PS 5800 RPM there is no change in engine gearbox from 2001 May to 2006 June.
If u want to drive at 2,000 RPM and watch Alto & Cuore overtake you from wrong side you may achieve 9km/L max in summer from a VTi.
The Steermatic 1.5L VTEC and 1.2L IDSI Vario shape city are nearly 40-50% more fuel efficient as they have the all new design L series engines and Civic has the decades old D series.
The 2003 Vti and 2004 are all same except for front lights.
VTi has ABS and Oriel model has sunroof dual MAP lights and retractable mirrors.
For city driving EXi is much more fuel efficient and engine is also much more reliable on CNG and automatic also.
My 2 Exi have mashAllah done more than 200,000 km without any engine overhaul.
I had almost kept and sold 18-20 of these civics with family and sons. Still have 2 EXi, one cateye Prosmatec and one Eagle Eye M/T and one UG grade VTi Prosmatec car on petrol.
My honest advice for u would be to buy a 2004 May-June EXi PROSMATEC with Eagle Eye clean car will cost you 800,000 in excellent condition.
There is no point of buying this car in manual transmission.