VPN options and and using non-standard ports

Do I understand correctly that the following are the options for a VPN server to allow access from a PC, from least secure to most secure:

PPTP

L2TP

L2TP over IPSEC

I want to set up my ER-X on my home network as a VPN server accessible from within my work network, but only ports 80 and 443 are guaranteed to not be blocked. When I read the various posts on configuring VPN, I see reference to the following ports:

PPTP:

• PPTP - TCP port 1723
• GRE - protocol 47 

L2TP:

• L2TP - UDP port 1701

IPSEC:

• IKE - UDP port 500
• ESP - protocol 50

NAT Traversal:

• NAT-T - UDP port 4500 (if using NAT-T)

So is there a way to set up L2TP over IPSEC with only 80 and 443?