upgrading NWDI from NW04 SP24 to SP25

Hi all,

At present we have NW04 SP24 Portal and following components

SAP_MSS-->100 SP20

SAP_ESS-->100 sp20

BP_ERP4ESS-->60.2 SPnull

BP_ERP4MSS-->60.1 SP1

SAPDEVINFF-->6.40 SP24

SAP_DEVINF-->6.40 SP24

Here we have following concerns about the upgrade to SP25

1.is it required to upgrade ESS and MSS and anything on ERP side along with Portal upgrade to Sp25

2.After upgrade NWDI to SP25, all the present tracks with custom components will work as it is?without any changes to it

or we need to build it once again from scratch, beacause we have lot custom components as well as ESS customization also

Can please provide any supporting documents and notes related above questions

Thanks & regards

Gopal