Sure mate - to give you an idea I work for company in London and my responsibilities are these (just to give you an idea of my role, I am sure there are guys on here with some seriously cool jobs but this is just mine and what I do // have done in this role):
1. VMware vSphere 4.1
2. XenServer 5.5 (5.6 has performance issues, so we have avoided it)
3. XenApp 5 (deployed 6 on Windows 2008 R2 but had nothing but problems with it, that said, this was a while ago now)
4. XenDesktop 4
5. SQL Server 2008 // 2005 // 2000
6. Windows Server (all of them including Cluster)
7. SAN's including hardware mirroring (NetApp FAS and the old SUN arrays)
8. iSCSI (MD3000i // NetApp // VMware)
9. Linux // Solaris // basic AIX
10. Avaya
Thats pretty much what I have to do in a week, I know the hardware side but we have support contracts for that so any hardware faults we try to fix on site, if we cant we call Dell // HP // NetApp etc etc and most of the time they know that down time is critical, so they usually just replace everything in one hit, that includes procs and raid controllers, nobody really builds anything now as it is all mass produced
If I were to start again going by the market today (this is just my own opinion not necessarily the right one) I would go for a CCNA and the Microsoft Certififcations, also grab yourself a nice 6 core system from OcUK, build it and stick VMware ESXi on it (and XenServer), play around with it, I would especially go down the Citrix route because many of the citrix certifications don't require you to go on a course, this is a huge advantage over vmware because for the vcp you have to go on the course and it is over £1k, you dont need to do this for a cca (citrix xenserver) just study the admin guides online and pay £80 for the course, then your certified!
technology id play around with if i were you:
xenapp (30 day trial)
xendesktop (Really really cool, desktop virtualisation, google xendesktop express, its free for 10 desktops!)
vmware esxi
mono (run .net apps in linux)
centos (basically red hat but free)
windows certifications (subscribe to msdn its cheap and you can play with all the new tech)
ccna (this is what im doing now as i have never bothered with cisco // networking but wish i had)
development (.net and java)
aim for the certifications you can get without having to attend a course like the ccna, cca (citrix) etc
forget system building // hardware
just my opinion, not necessarily the right one
EDIT: I forgot to add, use jobserve.co.uk, its a great tool to tell you what pays well and what that job expects, so search for system builder, SAN, vmware, vcp, ccna, ccnp, mcse etc in role section, check the pay for your area, gives you an idea whats in right now, at the end of the day the market defines what you should know