Monoprice center in-wall speakers underpowered?

Complete newbie here so pardon my ignorance. I checked other post couldn't get the info I was looking for.

I am putting together a 7.1 system. I plan to buy Onkyo NR809 that delivers 135W per channel. I need to decide the center speaker that is in-wall (goes just below the TV) and suits the receiver. I have other monoprice in-wall 3 way speakers as L and R (product# 7607) and 4 X 8" 2-way in-ceiling as rear surround (#4104).

I am considering the monoprice center in-wall speaker (# 4881) but it has power rating of 100w max and RMS 50w. So the questions are

1. Is this power rating good for center channel? I have a living room 16' x 27' (TV and center and L&R on 18' wall) and will this power be enough to have a decent experience especially because this is the center channel?

2. Do I run a risk of burning my speaker if I crank up the center channel that may deliver 135W?

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As a follow up question, if Monoprice is not suitable for this situation do the gurus on this forum have any suggestion for in-wall center speaker than suits my requirement? I checked out Polk LCi-C and 255c (vanishing series); they have power rating of 10-150W but they are bit pricey as well.

I will really appreciate any advice.

Thanks ljo000. I checked out your suggestion. The reviews on monoprice.com for it don't give much information (rather seem to suggest that it flatter on bass). Does any one here already use it and would you suggest it as center channel speakers.

I also need to make a correction. The L and R speaker I have aren't 7607. They are 6816 which are bigger (8") and have better power handling capability.

Any opinion about the Polks referred above? Any other suggestion for broad range reasonably priced in-wall center speakers that can handle the power?

When you select a speaker,
1. should the speaker rating more or less match the receiver output OR
2. should speaker have power rating above what receiver delivers so that it doesn't get blown away OR
3. Speaker should have power rating lower than receiver so it fails before you cause any damage to receiver?