SharePoint 2010 Server roles with 10 servers

Hi, 

Need some <g class="gr_ gr_24 gr-alert gr_gramm Punctuation only-ins replaceWithoutSep" data-gr-id="24" id="24">opinions</g> please. 

I am configuring a script for a farm and are in 2 minds.

4 of the 10 servers are going to be WFE Servers.

So how do <g class="gr_ gr_26 gr-alert gr_tiny gr_spell ContextualSpelling multiReplace" data-gr-id="26" id="26">i</g> split the additional 6 <g class="gr_ gr_27 gr-alert gr_gramm Punctuation multiReplace" data-gr-id="27" id="27">Servers.</g>

This is my thinking:

2 x App Servers (MMS, UPS, State, Web Analytics, Usage and Health, Secure Store, BDC, Access Services, Visio, )

1 x Search Servers (All Search Functions)

2 x BI Servers (Excel Services, PowerPivot, Performance Point, SSRS(There is dedicated SSRS Servers but this for config parts)

Then still have a Spare Server. Not interested in Web Apps. Thought of Second search server but search not huge priority.

Lots of BI happening so maybe even splitting that to 3rd server? 

Thanks for your input.