Rear Cassette and Hubs question

[Shropshire65LW]

this may be a stupid question
i have a specialized crosstrail hybrid, i want to replace the components as they have seen there life in a unloved bike
i bought ...compatibility seams a complicated thing

im going to replace my rear cassette , but believe my Hub determines what i can fit .. I assume as its a 9 speed shimano
any 9 speed shimano will fit

and any 9 speed Rear derailleur will fit

my other prob is it seams to be a unusual fitting front derailleur . thats a top swing , bottom pull , were the
fixing bracket is lower than the changer and pulls from underneath the bottom bracket .

i was hoping to replace and upgrade this . But seams i can only find a Acera ......and i was hoping to fit Deore XT

I think ive sourced a XT rear cassette and rear derailleur ...just the front im struggling with

Appreciate any help thanks

 

[rogerzilla]

That's a normal clamp-on, bottom-pull triple derailleur. Yes, any 9 or 10 speed Shimano rear mech of similar cage length will fit but stick to an MTB front mech as a road triple mech will not play with your MTB shifters. Unless they are thumbshifters, which is unlikely these days!