You must be very careful to consider what applications are pushed across the SSL-VPN. Clientless SSL-VPNs are web-based by nature and use the gateway as a proxy to the inside network. If you need a true client-server application, then this probably will not work.
There are SSL-VPN perishable clients that can use Java or ActiveX applets for some of this (which can usually be pushed to the client), and there are even thick SSL-VPN clients in some cases that can mitigate this issue, however, it is dependent on vendor and application.
My general experience with this is that IPSec is still the king as it will allow for ANY IP-based application regardless of application, whereas SSL is usually only a fit for web-based apps in environments where you can't control nor able to deploy thick clients easily.
I hope this helps.
-HH